Warp nacelles contain a number of field coils which create a warp field when injected with highly energetic warp plasma, or plasma created in the warp core by the reaction of deuterium and antideuterium, mediated through an assembly of dilithium crystals, which are nonreactive with antimatter when subjected to high-frequency electromagnetic fields. The warp nacelle is connected to the warp core via plasma transfer conduits, which transferred the plasma in the core to the nacelles. Because the radiation produced by a nacelle was detrimental to living beings, the nacelle was usually placed at some distance from the main structure of the vessel, and held in place with a pylon.

On Starfleet vessels, nacelles often have a Bussard ramscoop at the front of the nacelle, which gathers hydrogen for use in power generation.